Recently, research and development of secondary batteries has been actively carried out. Here, the secondary batteries, which are rechargeable batteries, represent both conventional Ni/Cd batteries and Ni/MH batteries and up-to-date lithium ion batteries. The lithium ion batteries among the secondary batteries have the merit of high energy density compared to the conventional Ni/Cd batteries or Ni/MH batteries. Furthermore, the lithium ion batteries can be made small in size and light in weight, and are thus used as power sources of mobile devices. Moreover, since the scope of use of the lithium ion batteries extend to power sources of electric vehicles, the lithium ion batteries attract attention as next-generation energy storage media.
Meanwhile, a battery pack state monitoring system used in a vehicle requires a high-level safety mechanism so as to monitor, without error, situations that may be dangerous for a vehicle or a driver. For example, a BMIC of a battery management system (BMS) of an electric vehicle measures state information such as a voltage, a current, a temperature, and the like of a battery pack by controlling operation of a cell monitoring unit such as an analog front end (AFE), and generates a diagnostic signal from the measured state information to transfer the diagnostic signal to a main MCU and an auxiliary MCU via communication in a vehicle. The main MCU and the auxiliary MCU receives the diagnostic signal from the BMIC to monitor the state of the battery pack. Here, since the operation of monitoring the state of a battery pack per se directly affects the safety of a driver, constituent units for monitoring the state of a battery pack should be designed to satisfy safety requirements.
In order to satisfy high-level safety requirements, conventional battery pack monitoring systems employ a technology for measuring and diagnosing a battery pack by additionally designing a BMIC and a circuit stage or a technology for measuring and diagnosing a battery pack by replacing an existing main MCU for a battery pack monitoring system with a high-performance main MCU having specifications that satisfy high-level safety requirements.
However, the technologies for designing the conventional battery pack monitoring systems for satisfying high-level safety requirements have a problem wherein the cost for production increases. Furthermore, according to the technologies for designing the conventional battery pack monitoring systems, the size of a manufactured product increases since the volume of a BMS increases due to the additionally designed BMIC and circuit stage.
Therefore, it is required to develop a battery pack state parallel-monitoring device, which enables the achievement of a safety mechanism that satisfies high-level safety requirements without additionally designing a BMIC and a circuit stage in a battery monitoring system or replacing an existing main MCU with a high-performance main MCU.